Other Correlations
I changed the publication data column into a column of Years since 1974.

cor(good.doubled, Years, use="complete")
[1] -0.1879052 Not a strong correlation about Kings adapted books get better or worse since he started
> cor(good.doubled, Pages, use="complete")
[1] -0.02715659 no relationship between the length of a book and it being rated highly or lowly.
> cor(Years, Pages, use="complete")
[1] 0.482048 King's adapted books may be getting a bit longer over time